This invention provides a gaseous wave refrigeration device (GWRD) with a flow regulator, a wave impedor, and chiller to monitor the gaseous wave behavior in GWRD and to produce the refrigeration effectively. This characteristic is achieved by means of controlling resonant periodic flow phenomenon of gaseous column and wave interactions under varying conditions of flow states in pressurized supplying gas streams through GWRD.
As is known widely in the industrial fields, gaseous expansion refrigeration processes are applied in a variety of operations, such as condensation, gas separation, gas liquefaction, and oil refining of traditional chemical and petroleum industries. Meanwhile, the rapid development of small mechanical cryocoolers in the high-tech fields which use the gas expansion cycles over the past decades is due to the emergence of specific applications in low-temperature operation with the requirement of a long life running. All of them are operated under pressurized gases expansion processes or relative gaseous expansion cycles. The primary feature of gas expansion cooling devices afore-mentioned is that the temperature drop or cooling load is obtained by the cycle extracting the energy or work from the expanded gases by mechanic parts--either the type of pistons, displacer, or impellers.
Generally speaking, gaseous cooling devices may vary according to different mechanic structure, device size, operating conditions, and thermodynamics cycles. However, they can all be classified by the cooling capacity and the range of applications of such a device in the systems. For instance, many gaseous expansion equipments such as turbines and piston expanders are designed for high cooling capacity mainly in petrochemical industries, whereas small cryocoolers such as G-M coolers, Stirling coolers, pulse-tube coolers, and adsorption cooler for the applications in infrared detectors for earth observation, night vision, and missile guidance are mainly designed to work under different working environments with small cooling capacity.
However, Almost all the current cooling devices designed have one common feature in terms of their cooling mechanism: they all have mechanically moving parts to absorb pressure energy from cold gases and to achieve the cooling effects. The utilization of mechanical structures in the gaseous expansion device improves the operation efficiency in thermodynamic cycles and increases the cooling effect. On the other hand, it causes the drawbacks of low running reliability, high cost of maintenance, limitation of operation conditions. Therefore, in past several decades new efforts had been made to develop the new type of gaseous expansion devices in order to overcome the fatal disadvantage in the traditional devices
Due to the development of new technology and the stimulation in the relative high-technical industries such as magnetic resonance imagery systems, superconductivity applications, and high energy facility, there has been an increasing interest in developing new devices for extreme special conditions with very high pressure drop, very lower temperature environment, long-life running, and fluctuating operating condition, etc. where the traditional cooling devices for gaseous expansions fail or lack inefficiency. In order to replace inefficient traditional equipment and retain merits of simple structure, low initial investment, and low maintenance cost, considerable improvements have been made in this field for the consideration of effective operation as employed in the previous arts by U.S. Pat. Nos. 2,765,045, 2,825,204, 3,200,607, 3,314,244, 3,541,801, 3,526,099, 3,559,373, 3,653,225, 3,828,574, 3,889,484, 3,904,514, 4,383,423, 4,444,019, 4,504,285, 4,531,371, 4,625,517, 4,722,001.
All the inventions have limited success in overcoming the problems mentioned, because they all contain some moving parts which will usually lead to low liability and high maintenance cost though some of them are operated on the improved mechanism or structure. Generally, in order to avoid the mechanically moving parts as required by system reliability, Joule-Thomson valves (throttling valves) have to be used as the element to obtain cooling capacity. The mechanism of the J-T valves is based on an isoenthalpic process during the pressure drop of gas expansion. Although it is still the most popular alternative for industrial gaseous expansion and pressure regulation processes owe to its simplicity, reliability, low cost maintenance, and easy controllability, nevertheless, J-T valves have a very low cooling efficiency which results in high loss of pressure energy in the gas cooling processes. Obviously, its wide application is due to the fact that to obtain cooling effect by pressure reduction in the certain technical processes, using throttling valves instead of traditional energy extracting machines is the only possible solution to the extreme working conditions such as high pressure and two-phase flow.
Therefore, a device which will increase the cooling efficiency without any mechanical moving parts and at the same time retain the merit of J-T valves always challenges the manufacture of gas expansion equipment and attract the industrial users.
In the previous arts, the idea to create cooling effect by means of gaseous wave interaction in periodic unsteady flows has already been proved and reported by U.S. Pat. Nos. 3,541,801, 3,653,225, 3,828,574, 4,625,517, 4,722,001, especially 5,412,950. However, none of the previous arts with these and other mechanism have ever proposed a device running effectively with the merits of no moving parts, simplicity, reliability, easy regulation, and low cost for maintenance under the varying flow conditions which frequently occurs in industrial practices. Therefore, the prior patents with these and other mechanism have limitations in terms of their efficiency, simplicity, controllability, and reliability in the scope of industrial applications. Although there are several devices which used a pulsating flow to generate cooling effect in prior art patents, there still exists no device with enough cooling capacity, free of complex structure and moving parts, and suitable for the controllability for flow state fluctuation like valves in industrial practice. In addition, it is also very difficult to find the existing gaseous cooling devices which can work effectively (or to be more specific limitation in cooling capacity, or won't have the required stable operation) under the condition of varying flow state in industrial systems within the high pressure drop range as well. These and other difficulties experienced with prior arts of gaseous cooling devices and the needs of engineering applications in the variation of operating flow conditions have been motivated in a novel manner of the present invention.
In comparison with traditional refrigeration equipment and the existing types of gaseous wave refrigeration devices in the previous arts, the present invention, for its primary object, introduces an apparatus, which works by using the mechanism of resonant gaseous wave for cooling processes under the varying condition of flow state. The present invention overcomes the limitations and weak points with the previous arts in terms of gaseous wave refrigeration device in U.S. Pat. No. 5,412,950.
The Applicant's apparatus in the present invention is designed for the GWRD operation under the varying condition of flow state in supplying pressurized gas stream, which is often met in all industrial systems and makes the GWRD operation inefficiency or failure. The apparatus's operation is established on the special mechanism to control gaseous wave resonance flow production for the best performance of GWRD by the mechanical regulating structure which can minimize the effect of flow state variation on the periodic gaseous wave system behavior. In addition, the apparatus in the present invention can also be adjusted to responses the variation of active flow state as required by monitoring processes in most industrial systems. The apparatus in the present invention is especially suitable for technical processes in industries where the flow state of supplying pressurized gas stream is needed to be monitored actively and adjustable manually to obtain the effective cooling operation, or the case in which the respondence has to be taken for the passive fluctuation of flow states in supplying pressurized gas stream due to undesirable reasons.
Most importantly, the present invention also improves over the previous art U.S. Pat. No. 5,412,950 which failed to produce cooling effect efficiently at varying flow state due to the change of gaseous wave interactions in the oscillating chamber. By contrast, the gaseous wave refrigeration apparatus in the present invention provides an effective instrument for systems and processes in petrochemical and natural gas industries where (a) conventional throttling valves have been used to generate the cooling effect, (b) the flow state passing the throttling valve is needed to be actively monitored and adjustable for the required variation of cooling load and optimized operation, and (c) the flow state changed passively due to the need of processes operation in which the maximum cooling effect is hardly obtained for the required load from existing throttling valves.
In short, the present invention aims at meeting several important objectives. The first is to provide a gaseous wave refrigeration apparatus for applications where traditional expansion machines can not be used or are used with low efficiency at varying flow states.
The second is to provide a gases wave refrigeration apparatus for replacement of throttling valves with a flow state regulator manually to monitor actively the recovery of the high pressure drop energy from the gaseous expansion processes in industrial systems.
The third is to provide a gaseous wave refrigeration apparatus to handle the flow state variation passively in industrial system and generate the maximum cooling performance by adjusting the wave interaction behavior in said gaseous wave refrigeration apparatus.
The last is to provide a gases wave refrigeration apparatus which can operate under the extreme high pressure drop by means of a multi-stage operation in series. Meanwhile, the flow state in each stage can also be controlled by means of a flow regulator in GWRD for maximum pressure energy recovery and cooling effect without using any moving parts.
With these and other objectives in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.